Summary This project is the next step in a research program designed to understand the pathophysiology and etiology of spite sensitivity, a theory-rich construct thought to underlie persecution and suspicious behaviors. We have developed a paradigm known as the Minnesota Trust Game that uses a parametric manipulation of risky decisions to quantify participants' suspicious behaviors. This game includes trials where the partner has an opportunity to be spiteful, that is lose their own money to cause the participant to lose even more money. Spite sensitivity, then, is reflected as an unwillingness to allow partners this opportunity. We have found across patient and healthy samples that this suspicious choice correspond to global judgments of persecution, paranoia and alienation. The project examines persecution in people receiving psychiatric services and twins from the general population using this game in a functional MRI scanner. The inclusion of psychiatric patients (n=50) and monozygotic twins (n=50 matched to patients and up to n=50 of their co-twins) allows us to examine the continuity of mechanisms across these populations. The inclusion of monozygotic twins also allows us to examine etiological factors and to evaluate causality. These tools therefore provide a robust test of the hypothesis that persecution is a form of spite sensitivity, a component the RDoC construct understanding others' mental states. Spite sensitivity, in turn, relates to a functional disconnection between executive control and valuation brain networks.